Developmental Assessment of Sexual Reproduction i

Authors: FERNANDO DANILO D CASS DAVID D

Publish Date: 1997/10/01

Volume: 80, Issue: 4, Pages: 457-467

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Abstract

DANILO D FERNANDO DAVID D CASS Developmental Assessment of Sexual Reproduction in Butomus umbellatus Butomaceae Female Reproductive Component Annals of Botany Volume 80 Issue 4 October 1997 Pages 457–467 https//doiorg/101006/anbo19970467Flowering plants often produce ovules that do not develop into seeds Lack of pollination insufficient resources environmental constraints and incompatibility reactions are often considered to be causal factors Prepollination and postfertilization developmental irregularities DI are less commonly implicated as causal factors usually because information on them is limited The results of a detailed developmental assessment of sexual reproduction in B umbellatus using self and crosspollinated glasshouse and openpollinated fieldgrown plants reveal a high degree of prepollination and postfertilization DI Prepollination DI account for a large fraction of the species low reproductive potential Postfertilization DI represent another crucial reduction in the species reproductive output Seed set in B umbellatus is less than 1 In the female reproductive component these DI include embryo sacs with hypertrophied or highly vacuolate eggs collapsed synergids collapsed egg apparati and embryo sacs that are empty uninucleate or with disorganized mass of nuclei there are also ovules with no embryo sacs Postfertilization DI include zygotes that are hypertrophied highly vacuolate and collapsed and malformed embryos The lack of an obvious adaptive significance to the array of DI in B umbellatus suggests that these are unlikely to be due to selfincompatibility reactions and physiological or environmental constraints Since B umbellatus is a longlived species it is highly possible that disadvantageous mutations have accumulated in its clonal lineages causing a considerable load in terms of faulty meiosis resulting in defective meiotic products a series of DI and therefore limited sexual reproduction

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